Total depth after etching is 8.869 um
Calculated remaining resist as 8.24um, indicating an erosion of 0.50um in 10 minutes of etching
This equates to an erosion rate of 50 nm/min
The etch depth of 0.63um in 10 mins indicates an etch rate of 63.0nm/min
The selectivity is therefore 1.25:1